﻿using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Drawing;

namespace GMusicBox
{
    public partial class LabelX : Label
    {
        int lineDistance = 5;

        public int LineDistance
        {
            get { return lineDistance; }
            set { lineDistance = value; }
        }


        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            String drawString = this.Text;
            Font drawFont = this.Font;
            SolidBrush drawBrush = new SolidBrush(this.ForeColor);
            SizeF textSize = g.MeasureString(this.Text, this.Font);//文本的矩形区域大小   
            int lineCount = Convert.ToInt16(textSize.Width / this.Width) + 1;//计算行数   

            this.Height = Convert.ToInt16((textSize.Height + lineDistance) * lineCount);//计算调整后的高度   
            this.AutoSize = false;
            float x = 0.0F;
            //float y = 0.0F;
            StringFormat drawFormat = new StringFormat();
            int step = 1;
            lineCount = drawString.Length;//行数不超过总字符数目   
            for (int i = 0; i < lineCount; i++)
            {
                //计算每行容纳的字符数目   
                int charCount;
                for (charCount = 0; charCount < drawString.Length; charCount++)
                {
                    string subN = drawString.Substring(0, charCount);
                    string subN1 = drawString.Substring(0, charCount + 1);
                    if (g.MeasureString(subN, this.Font).Width <= this.Width
                    && g.MeasureString(subN1, this.Font).Width > this.Width)
                    {
                        step = charCount;
                        break;
                    }
                }
                string subStr;
                if (charCount == drawString.Length)//最后一行文本   
                {
                    subStr = drawString;
                    e.Graphics.DrawString(subStr, drawFont, drawBrush, x, Convert.ToInt16(textSize.Height * i) + i * LineDistance, drawFormat);
                    break;
                }
                else
                {
                    subStr = drawString.Substring(0, step);//当前行文本   
                    drawString = drawString.Substring(step);//剩余文本   
                    e.Graphics.DrawString(subStr, drawFont, drawBrush, x, Convert.ToInt16(textSize.Height * i) + i * LineDistance, drawFormat);
                }
            }
        }
    }   
}
